Cylinder head for internal combustion reciprocating engines



July 24, 1962 3,045,655

A. FQRMIA CYLINDER HEAD FOR INTERNAL COMBUSTION RECIPROCATING ENGINES Filed March 22, 1961 2 Sheets-Sheet 1 July 24, 1962 A. FORMIA CYLINDER HEAD FOR INTERNAL COMBUSTION RECIPROCATING ENGINES Filed March 22, 1961 2 Sheets-Sheet 2 United States Patent Ofi ice 3,045,655 Patented July 24, 1962 3,045,655 CYLINDER HEAD FOR INTERNAL COMBUSTION RECIPROCATING ENGINES Antonio Forrnia, Turin, Italy, assignor to Fiat Societa per Azioni, Turin, Italy Filed Mar. 22, 1961, Ser. No. 97,530 Claims priority, application Italy Apr. 30, 1960 4 Claims. (Cl. 123-30) This invention relates to a cylinder head for reciprocating internal combustion engines, more particularly of the diesel type.

The object of this invention is to provide an engine cylinder head, in which the arrangement in plan view of the intake and exhaust valves leads to an arrangement of induction conduits adapted to effect a double helical turbulent flow in the cylinder.

According to this invention the induced air reaches the inside of the cylinder in a condition subdivided into two helical turbulent flows by virtue of which it is distributed within the cylinder in such manner as to facilitate and activate the combustion process.

The improved cylinder head is substantially characterized by the fact that it comprises in association with each cylinder two separate poppet valve controlled induction conduits each of which opens into the cylinder in a direction downwardly and tangentially of the cylinder so that the air drawn into the cylinder is subdivided into two helical flows directed substantially downwardly.

Moreover, according to this invention, the intake valves are operated by means of a single rocker and push rod.

Further characteristic feature and advantages will be understood from the appended detailed description referring to the accompanying drawings given by way of a non limiting example, wherein:

FIG. 1 is a part sectional elevational view of the head and FIG. 2 is a plan view thereof.

On the drawings the head 1 is secured in a known manner to the engine block by means of stud bolts 2 and comprises a cover 3 confining a chamber housing the rockers for the valve gear and valve return springs.

In association with each cylinder the head is formed with a seats for a pair of intake and exhaust poppet valves 4, 5, respectivly.

The valves 5 control their respective branches of a bifurcated exhaust conduit 6, the branches having a common outlet section 611 opening on one side 1a of the cylinder head with respect to a longitudinal vertical plane AA of the engine.

The valves 4 control a pair of separate intake conduits 7, 8 respectively, which are downwardly curved when seen in elevational cross-sectional View (FIG. 1) and open into the cylinder in directions which are co-current and substantially tangential (circumferential) with respect to the cylinder when seen in cross-sectional plan view (FIG. 2) whereby two co-current helically downwardly directed flows of combustion air are induced in the cylinder during each suction stroke of the engine.

In order to increase the whirl of the air flows in the cylinder, a bafile such as 7a is cast-formed on an intradorsal surface of each intake conduit 7, 8 at a location adjacent its respective valve head, thereby to substantially prevent the air flow from being part-deflected backwardly in the direction C (FIG. 1) by the valve head and thereby to direct the bulk of induced air in direction D over and beyond the edge section of the valve head which is remote from the bafile.

The inlet sections of the intake conduits 7, 8 open outwardly on a lateral side 1b of the cylinder head which is opposite to the side 1a, whereby intake and exhaust manifolds can be easily fitted to the head.

Such an arrangement of intake and exhaust conduits is made actually possible by a particular arrangement of valves 4, 5 visible on FIG. 2. It will be seen that the intake valves 4 extend parallel therebetween on a plane EE which is a chordal plane with respect to the cylinder 15 forming an acute angle with the longitudinal axial plane AA of the engine, whereby the inner end sections of the intake conduits 7, 8 reach their respective valve seats without interfering with each other. The exhaust valves 5 are similarly arranged on a chordal plane forming an acute angle with plane AA and, in the preferred embodiment shown, all the valves are uniformly spaced around the geometrical axis of the cylinder. Intake valves 4 are actuated by a single rocker 10 acting on a bridge piece 16 seated on the stems of the valves 4. Exhaust valves 5 are similarly actuated by a single rocker 12 acting on a bridge piece 13 seated on the stems of the valves 5. The rockers are swingable on a common pivot supported from the cylinder head, the geometrical axis of the pivot being indicated by B-B in FIG. 2 and extending horizontally parallel with the plane AA at a location between the latter and the lateral side In of the cylinder head. The rocker arms diifer in length but the two rockers have equal lever ratios. The rockers are actuated in a known manner by means of push-rods (not shown) extending through a common passage 14 in the cylinder head towards their actuating camshaft. A fuel injector 9 is seated in the cylinder head on the geometrical axis of the cylinder having its tip 9:: projecting into the cylinder, as far as a diesel engine is concerned; a common spark plug can be substituted for the injector when the engine is an internal combustion engine of the Otto-cycle.

What I claim is:

1. In an internal combustion engine a cylinder, a cylinder head having a pair of separate downwardly curved elbow-shaped intake passageways having substantially the same lengths, each passageway having an inlet and an outlet port, both inlet ports being situated on the same side of the cylinder head, both outlet ports beings situated substantially tangentially to the wall of the cylinder and on the same side of a plane corresponding to a cylinder diameter making an acute angle with the longitndinal axis of said engine, said cylinder head having for each outlet port a seat formed circumferentially of each outlet port and an intake valve for each outlet port operable to a seated position and an unseated position.

2. In an internal combustion engine having means defining a cylinder, the improvement which comprises, a cylinder head having a pair of separate intake passage- 'ways of substantially equal cross-section and lengths, each passageway having an inlet port situated on a same side of the cylinder head and each having an outlet port and an elbow-shaped portion curving downwardly to respective outlet ports each disposed to discharge two separate, parallel, air streams downwardly, circumferentially and helically relative to the longitudinal axis of said cylinder, said outlet ports being disposed spaced relative to each other on the same side of a plane corresponding to a diameter of said cylinder, the centers of the outlet ports lying in a common plane corresponding to a chord of said cylinder and making an acute angle with the longitudinal axis of the engine, each passageway having a length thereof extending between its respective outlet port and elbow-shaped portion disposed to define a path for a volume of air-moving therethrough to move in a direction substantially tangential to the inner wall of the cylinder in a common area of a semi-cylinder defined by the firstrnentioned plane and the wall of the cylinder thereby to cause the air streams moving therethrough and through respective elbow-shaped portions of said passageways into the cylinder to move along a helical path downwardly through said cylinder when they enter said cylinder, said cylinder head having for each outlet port a seat formed circumferentially of each outlet port, and an intake valve for each outlet port operable to a seated position and an unseated position.

3. In an internal combustion engine a cylinder, a cylinder head having a pair of separate downwardly curved elbow-shaped intake passageways having substantially the same lengths, each passageway having an inlet and an outlet port, both inlet ports being situated on the same side of the cylinder head, both outlet ports being situated substantially tangentially to the cylinder wall and on the same side of a plane corresponding to a cylinder diameter making an acute angle with the longitudinal axis of said engine, said cylinder head having for each outlet port a seat formed circumferentially of each outlet port and an intake valve for each outlet port operable to a seated position and an unseated position, in each intake passageway a bafile formed by a lip extending radially away from a part of the circumference of respective intake passageways, and each of said bafiles being arranged adjacent each valve seat and on the upstream side of said seat so as to shield a peripheral portion of the outlet port and direct the air stream to the far side of said outlet port and toward the cylinder wall.

4. In an internal combustion engine having means defining a cylinder, the improvement which comprises a cylinder head having a pair of separate intake passageways of substantially equal cross-section and lengths, each passageway having an inlet port situated on a same side of the cylinder head and each having an outlet port and an elbow-shaped portion curving downwardly to the respective outlet ports each disposed to discharge two separate, parallel, air streams downwardly, circumferentially and helically relative to the longitudinal axis of said cylinder, said outlet ports being disposed spaced relative to each other on the same side of a plane corresponding to a diameter of said cylinder, the centers of the outlet ports lying in a common plane corresponding to a chord of said cylinder and making an acute angle with the longitudinal axis of the engine, each passageway having a length thereof extending between its respective outlet port and elbow-shaped portion disposed to define a path for a volume of air moving therethrough to move in a direction substantially tangential to the inner wall of the cylinder in a common area of a semi-cylinder defined by the first-mentioned plane and the wall of the cylinder thereby to cause the air streams moving therethrough and through respective elbow-shaped portions of said passageways into the cylinder to move along a helical path downwardly through said cylinder when they enter said cylinder, said cylinder head having for each outlet port a seat formed circumferentially of each outlet port, and an intake valve for each outlet port operable to a seated position and an unseated position, in each intake passageway a batlle formed by a lip extending radially away from a part of the circumference of the respective intake passageway, and each of said battles being arranged adjacent each valve seat and on the upstream side of said seat so as to shield a peripheral portion of the outlet port and direct the air stream to the far side of said outlet port and toward the cylinder wall.

References Cited in the file of this patent UNITED STATES PATENTS June 26, 1958 (K1 46A210), 1 sht. dwg. 2 pp. spec. 

